The long and varied coastline of the Korean Peninsula is home to plants that thrive in the transition zone between terrestrial and marine ecosystems. The Korean east coast, and the volcanic island of Ulleungdo facing it, is a region where species populations and lineages are allopatrically distributed, including those of the seashore spatulate aster (Aster spathulifolius Maxim.). In this study, we examined the disjunct distribution of this coastal specialist by employing genome-wide SNP markers to evaluate its genomic diversity and structure, and infer its number of independently evolving lineages in this region. Our findings suggest that the genetically distinct population structure between the peninsular and island distributions, and the significantly reduced genetic variation patterns, more so for the insular populations, appeared to be the classic signatures of the mainland-island model. The vicariant population distribution was further found to be delineated by a genetic barrier, i.e., the East Sea geographic break, although isolation by distance may have also influenced the divide. Along with the molecular line of evidence, the nomenclatural and taxonomic implications of the findings are also discussed in this paper.
Transcranial alternating current stimulation (tACS) is a noninvasive brain stimulation method that modulates neural activity by applying low-intensity alternating current to the scalp. Although tACS has shown promise in enhancing cognitive and motor functions and alleviating neuropsychiatric symptoms, variations in stimulation parameters led to inconsistent outcomes. While stimulation frequency and electrode montage have been extensively explored, systematic analyses focusing on stimulation duration remain limited. Resting-state EEG, recorded under relaxed conditions without specific tasks, minimizes variability due to individual performance and external factors, thus providing a stable measure of tACS-induced neuromodulation. Therefore, we aimed to investigate the differences in neuromodulatory effects between three tACS durations for effective neuromodulation using resting-state electroencephalography (EEG). Ten participants completed three randomized tACS sessions on different days, each with a duration of 10, 20, or 30 min. Resting-state EEG was recorded before and after stimulation under eyes-open (EO) and eyes-closed (EC) states. Power spectral density (PSD) and network indices were analyzed for neuromodulatory effects. The omnibus analysis revealed no significant main effect of stimulation duration on neuromodulatory outcomes. However, within-condition analyses revealed significant increases in PSD in the post-tACS EO recording after 10 min (r = 0.79) and 20 min (r = 0.66), whereas in the post-tACS EC recording significant increases were observed only at 10 min (r = 0.63). Network efficiency also increased significantly in the EO state after 10 (r = 0.79) and 20 min (r = 0.85) for clustering coefficient and after 10 (r = 0.73) and 20 min (r = 0.85) for path length, respectively. Moreover, the observed patterns differed between brain states, with more consistent effects observed in the EO state. These findings suggest that neuromodulatory responses may vary depending on both tACS duration and brain state, highlighting the importance of considering both factors in the design of tACS protocols and interpretation of neuromodulatory effects.
Purpose: This review aimed to summarize the recent prevalence , epidemiological characteristics of endemic parasitic in- fections in Korea as reported in the literature up to 2026. Current concepts: Data were collected from national surveillance statistics of the Korea Disease Control and Prevention Agency and from studies indexed in PubMed and KoreaMed published between January 2019 and February 2026. The overall prevalence of intestinal helminth infections has decreased substantially , infections such as ascariasis and trichuriasis (0.2%) are now rarely detected. However, clonorchiasis remains relatively prevalent in endemic river-basin regions (2.3% in 2024), reflecting persistent dietary habits involving the consumption of raw freshwater fish. Vivax malaria continues to occur near the Demilitarized Zone despite long-term control efforts (601 cases in 2025). Claims-based data showed an average of 422 cases of toxoplasmosis per year from 2007 to 2020, and the true burden may be underestimated because many infections are asymp- tomatic. Other parasitic diseases, including trichomoniasis (age- and sex-adjusted infection rate, >800 per 100,000 women aged 20-39 years in 2020) and scabies (age-adjusted infection rate, 43.0 per 100,000 in 2021), persist because of behavioral and demographic factors. Discussion and conclusion: Clonorchiasis still shows a relatively high infection rate in certain endemic areas. Malaria, toxo- plasmosis, trichomoniasis, and scabies may continue to occur because living environments and behavioral patterns are difficult to change. These parasitic diseases should be considered in the differential diagnosis in clinical practice, and patients should be evaluated with appropriate testing and referral when indicated.
Generative artificial intelligence (AI) is rapidly expanding within medical practice, yet its use among nuclear medicine professionals has not been systematically evaluated. This study provides the first society-wide assessment of generative AI adoption among members of the Korean Society of Nuclear Medicine (KSNM). An anonymous online survey was distributed to approximately 670 KSNM members. The questionnaire assessed AI use in two domains (research/education and clinical practice), including platforms, frequency, purposes, and perceived usefulness and trust. Descriptive statistics and chi-square tests were used. A total of 122 members responded (estimated response rate, 18.2
The purpose of this study was to analyze morphological variations of the sacrum in a Korean population, with particular emphasis on the number and configuration of sacral foramina in relation to lumbar vertebral count. We aimed to describe sacral morphological features that may occur even in the absence of overt transitional anomalies and to highlight potential limitations of conventional definitions based solely on lumbosacral fusion. Postmortem computed tomography (PMCT) data from three Korean individuals were reconstructed into three-dimensional models using Mimics software. Sacral segmentation patterns, lumbar vertebral counts, and key morphometric parameters were documented for each case. The measured parameters included sacral length (SL), sacral width (SW), superior transverse diameter (STD), and the vertical diameter of the sacral auricular surface (VDSA). Each case demonstrated a distinct sacral morphology. Case 1 exhibited five lumbar vertebrae, unilateral non-fusion of the L5 transverse process, and asymmetric sacroiliac articular surfaces (SL 137.5 mm; SW 119.5 mm; STD 52.6 mm; VDSA 66.9 mm right, 58.9 mm left). Case 2 showed four lumbar vertebrae due to bilateral L5–sacral fusion, accompanied by asymmetric fusion patterns and an indistinct S1–S2 boundary (SL 122.4 mm; SW 113.3 mm; STD 53.1 mm; VDSA 59.1 mm right, 60.1 mm left). Case 3 demonstrated five lumbar vertebrae and a six-segmented sacrum (S1–S6) with symmetrical auricular surfaces (SL 128.9 mm; SW 105.6 mm; STD 53.2 mm; VDSA 69.4 mm right, 70.7 mm left). These findings suggest that sacral elongation and remodeling of the auricular surface may occur independently of lumbar vertebral number. This highlights the importance of individualized morphometric assessment in clinical procedures such as sacroiliac joint fusion and caudal epidural anesthesia. Conventional definitions based solely on L5–S1 fusion may not adequately capture the complexity of sacral structure. Consideration of both sacral segmentation patterns and lumbar vertebral counts may enhance anatomical interpretation and clinical applicability.
